Level 1

9 points

6TB drives won't mount after restart in Mac Pro 2012

The problem manifests itself when a 6TB HGST drive does NOT mount on the desktop nor appears in the Disk Utility after a reboot. The ONLY way I have figured out how to work around this problem is to shut down the computer and the open the case and slightly pull out one 6TB hard drive (i.e. enough to release it from the SATA connector on the logic board) and then push it back in. At that point, if I boot the computer any and all 6TB HGST drives installed in the computer will appear on the desktop until I restart the next time. I don't have to remove each and every drive to make them all appear, just one.

When I first experienced this issue, I assumed it was a hardware problem with that one computer, but I have now experienced it again with a different computer at the different company and with a 6TB HGST drive from a different production batch. Now that I have two data points, I want to test this configuration on other computers to see if I can figure out if it is more widespread than the existing two machines.

The similarities between the two machines are more than the differences. They are both Mac Pro 2010 5,1 models at their core, but they are also both the 2012 variant that was a slight upgrade from the 2010 model. They both have the shipping EFI firmware (which is the latest for that model). They both have 20GB of RAM and they both run Mac OS X 10.8.5. One machine is used for graphic design and the other is a server. They also both have more than one drive slot being used. The one machine that is the server have four drives. Two are 2GB drives used as the boot partitions. The last two are 6TB data drives. The other machine that is used for design has two 2TB drives for booting and backup and one 6TB drive for Time Machine (the fourth slot is empty). In both cases the 2TB drives are Toshiba drives (using the HGST derived manufacture process). Also in both cases the two 2TB drives are in slot 1 and 2 and the 6TB drive(s) are in 3 or 3 and 4. They both have ATI Radeon 5770 cards. Both are plugged into Ethernet networks and do not have wireless turned on.

There are some differences too. The server has a number of external RAID boxes connected via an ESATA card. The other computer has nothing in the PCI-E slots. The server has an after market replacement DVD and the graphics machine has its stock DVD drive. The server machine runs OS X Server.app.

I have a number of resources at my disposal so I plan to do some further testing. That said, I don't have everything to be really thorough and would love some help from others whom are either experiencing this or just want to help. Here is what I don't know and would like to test.

I have in my world Mac Pros that I can test at different customer locations. I can test a 1,1 easily, and I can also test a 3,1 and 4,1. I have those all available in my direct control right now. What I don't have is a 5,1 2010 model, but I can borrow one to test. I can also procure another 6TB HGST drive. What I don't have is a WD 6TB or other brand. I would love to know if this is specific to HGST or if it is a general problem for 6TB drives, Also, for that matter, I would love to see if this happens with 5TB drives. Has anyone else installed a HGST or WD 6TB and had mounting problems?

It would also be great to know if this issue is independent of OS. I plan to test 10.6, 10.8, and 10.10. Of course on the 1,1 Mac Pro I can't test past 10.7. I also would like to know if it matters that a 2TB drive is present and even if that drive is a Toshiba or other brand and even the quantity of drives and their slot position. I hazily remember trying to move drives around in slots when I first encountered this problem. I also wonder if different models of the 6TB drive may behave differently (i.e. NAS versus Enterprise).

I plan to post my results when I am done with the testing.

Mac Pro, OS X Mountain Lion (10.8.5)

Posted on Jul 16, 2015 11:26 AM

113 replies

Jun 28, 2017 7:16 AM in response to Adam Wunn

I'm planning to swap my 6TB HGST drive into my Time Capsule and put a different 6TB Drive into my Mac Pro.

Can anyone confirm a current generation 6TB drive that does remount properly after restart? Preferably one that is compatible with the stock drive sleds?

Terry C

Level 1

69 points

Jul 15, 2017 4:51 PM in response to Grant Bennet-Alder

I'm having the same problem with two [Model: HGST 2TB HUS724020ALE640 UltraStar 7K4000 HDD] drives I purchased from B&H Photo 29-day ago. I just sent them an email regarding my desire to return them.

B&H also carries Model: HGST 4TB HUS724040ALE640 UltraStar 7K4000 HDD. This model has nine 4-5 star reviews.

In December 2014 this 4TB drive was reviewed by a customer who stated: "Great drives! Added to a Mac Pro to build a server as a replacement for aging G4 servers."

The problem is obviously unique to Mac Pro 4,1 and 5,1 models. I have the 5,1 2010 model. I was able to load OS X 10.6.4 from the CD that shipped with the computer, and it restarted on the 2TB HGST drive. However, neither of the drives mounted on the desktop. My OWC Mercury firewire back-up drive did mount. The HGST drives would not mount, even after a full shut-down and re-start with the computer booted into the 10.6.4 partition. So I shut down again, and reinserted the original 1TB drive that shipped with the computer. When I started up with an OS X 10.8.5 partition on that drive, it appeared along with the OWC firewire drive, but the HGST drives did not mount. After a full shut-down and re-start they did mount, exhibiting the same problems discussed here.

As I could not find a way to post at the end of this discussion, I thought I'd reply to Grant Bennet-Alder, who helped me a great deal with my: "Eternal Beige G3-333 Quandaries" back in the day.

Sure would be nice if someone could develop a discussion aimed at determining the best "Enterprise Class" hard drives that are available for Mac Pro 2009-2012 [Model: 4,1 & 5,1] computers.

The 4TB drives are $95 more than the 2TB drives at B&H. 4TB would give me plenty of space, but HGST drives are clearly an iffy proposition with these Mac Pros. I might try the 4TB drives if B&H is prepared to swap out these drives and give me a full refund if they do not work. I need two drives -- and again -- it's a quandary!

Terry C

Level 1

69 points

Jul 25, 2017 1:50 AM in response to timosx

Specs provided on the websites of both CDW and Best Buy indicate that the drive you have:

HGST hard drive Model: HUS726040ALE610; MFR Part# 0F23005, is designed to operate in a PC.

Shortly after I posted my previous message, I discovered that:

The hard drives I ordered, Model: HUS724020ALE640; MFR Part #0S03593, were not in the box.

The drives in the box were Model: HUS726020ALE614; MFR Part #0F23029, also design for PC.

I found an actual spec sheet for the drives I received and returned them, but HGST / Western Digital / AKA Hitachi has rendered the task of finding specs for their drives pretty difficult. Their claims that PC drives will format for Mac OS X are complete BS. Perhaps it's time for HGST to retain some QC personnel in Thailand to ensure that the part numbers on the box match the part numbers of the drives inside the box; and the prolific number of malfunctioning hard drives that people are discussing in this forum sound like the "stuff that makes the world go around" for attorneys.

I'm just "spit-balling," but based on what I read here and in various reviews it appears that:

HGST 4TB HUS724040ALE640 UltraStar 7K4000 HDD work well with the Mac Pro 5.1.

Clearly, the HGST UltraStar 7K6000 HDDs do not work well with the Mac Pro 5.1.

Check the MFR part numbers, against model numbers, and specs. If they're not right, return it.

Good luck.

Jul 25, 2017 6:02 AM in response to Terry C

Their claims that PC drives will format for Mac OS X are complete BS.

Disregarding for a moment that issues with spin-down&spin-up that make up this thread, If drive FORMAT were the only issue that statement is correct.

Kappy has observed that some Windows New Technology File System (NTFS) drives must be reformatted as MS-DOS first an intermediate step, then can be reformatted as Mac HFS+.

timosx

Level 1

4 points

Aug 25, 2017 9:02 AM in response to Adam Wunn

I've found a method so that I can use any problematics hard drives without the need for cold booting.

What I'm doing is preventing the problematic drive from mouting at boot. (I do this by editing the fstab file : with the terminal I add the hard drive UUID number to this file, you can check google for "how to prevent a volume from mounting at boot on osx" for more info).

I then use the free software "Semulov" to mount it from the menu bar but you can use disk utility if you prefer.

As strange as it may seem the hard drive now always appears in disk utility, even after restarting. it's just unmounted.

Without this trick I will lose my 4TB 7K6000 HGST Ultrastar hard drive each time I restart my mac pro (or switch between different OSX system partitions). Only a cold boot will bring it back to life.

kahjot

Level 4

2,469 points

Nov 19, 2017 11:12 AM in response to MacProUser9

It’s been reported here in other threads about the restart problem with certain drives that large WD Red drives work. Toshibas also work. I have an older WD Black that works, also. It would seem that a number of drives from recent Black series will not work.

lllaass

Level 10

210,799 points

Jul 16, 2015 12:51 PM in response to Adam Wunn

Are you using the standard sleds for the 8 TB drives?

If so are you using shortened mounting screws? If yo are then that might prevent the HD from properly aligning with the sled and thus it will not be aligned with the connector on the logic board.

OWC now sell a sled that uses the alternate mounting hols in the drive to prevent that problem.

kahjot

Level 4

2,469 points

Jul 16, 2015 2:42 PM in response to lllaass

http://eshop.macsales.com/item/OWC/MPRODBKTLG6/

Adam Wunn Author

Level 1

9 points

Jul 16, 2015 6:38 PM in response to lllaass

I appreciate the thought. I am aware of the problem with the sleds and from my understanding is that the problem occurs with some of the newer drives that have physical differences imposed by design changes (i.e. screw holes in a different spot) and cases that are shallower and therefore they have shorter screw holes. I know that this is the case with Western Digital drives. In my case I buy HGST drives and they are the traditional size and have screw holes in the exact same location as older drives. The drives fit perfectly in the sled and slide in a connect properly (at least it seems) and I can immediately format or mount a drive that is plugged in with the traditional sled. I can also leave that drive plugged in and working without incident until I restart the computer. It would seem to me that IF there were an issue, it would either be a physical impediment (i.e. I can't plug the drive in or the screw holes were in the wrong spot) or I would have some intermittent issues. At this point with the server that I have experienced this issue with, I have left it for over a month running without any issue. It only manifests if I restart the computer. I don't see how using an alternative bracket is going to make a difference. Maybe I am missing something and it will work, but if so, please someone explain it to me. I am willing to buy the bracket to test it, but it seems that my issue is different from the issue some people were experiencing with the Western Digital drive. Thanks again for the insight.

Jul 16, 2015 9:59 PM in response to Adam Wunn

large sized drives (over 2.2TB) have been supported since Mac OS X 10.4.4.

What has been a problem since 10.8.4 is a problem ERASing Internal drives over 2.2TB. They are set up as Logical Volume Groups and further partitioning and manipulation is impossible.

My speculation is that this feature has been partially repaired. Not in 10.8.5 it is not.

In Terminal, could you do a:

diskutil list

diskutil cs list

and post the output for one of the troublesome drives?

Adam Wunn Author

Level 1

9 points

Jul 16, 2015 10:34 PM in response to Grant Bennet-Alder

Thanks for the info and idea. Here is the terminal output. I see that one of the drives is reporting as a logical group. I am assuming that you suspected that was the issue? Is that somehow keeping the drives from mounting without intervention? From my experience, I have had issues reformatting drives that were erroneously identified as "logical volume groups" in the past and it took some fiddling to get them to reformat.

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *6.0 TB disk1

1: EFI 209.7 MB disk1s1

2: Apple_CoreStorage 6.0 TB disk1s2

3: Apple_Boot Boot OS X 134.2 MB disk1s

/dev/disk4

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS Data Backup *6.0 TB disk4

+-- Logical Volume Group CB1E5D46-005D-42CD-971C-70B5FBA91D8C

=========================================================

Name: Data Backup

Status: Online

Size: 6000831152128 B (6.0 TB)

Free Space: 0 B (0 B)

+-< Physical Volume 2221153D-CB65-4DB7-813C-BB958B6ECE92

| ----------------------------------------------------

| Index: 0

| Disk: disk1s2

| Status: Online

| Size: 6000831152128 B (6.0 TB)

+-> Logical Volume Family 4A1FFC18-2C36-4CAE-A80A-33B20278AAE3

----------------------------------------------------------

Encryption Status: Unlocked

Encryption Type: None

Conversion Status: NoConversion

Conversion Direction: -none-

Has Encrypted Extents: No

Fully Secure: No

Passphrase Required: No

+-> Logical Volume 4A6FD923-32AB-4712-B199-E1B7157A5749

---------------------------------------------------

Disk: disk4

Status: Online

Size (Total): 6000512376832 B (6.0 TB)

Size (Converted): -none-

Revertible: No

LV Name: Data Backup

Volume Name: Data Backup

Content Hint: Apple_HFS

Jul 17, 2015 8:02 AM in response to Adam Wunn

Yes, I am suspicious that Logical Volume Groups are the source of your trouble. Once you have eliminated physical alignment problems, there have been no other pervasive issues with very large drives reported here.

Readers have typically not been able to do anything with drives set up as Logical Volume Group, unless they intended to create a Fusion Drive or use all-disk encryption with File Vault.

The Logical Volume partitions can be deleted through careful use of Terminal. Typically opening a second window for cutting-and-pasting the long ID strings from diskutil cs list to delete them using diskutil in another window.

Readers can track down the old thread with that procedure if you would like to try that.

Adam Wunn Author

Level 1

9 points

Jul 17, 2015 1:11 PM in response to Grant Bennet-Alder

This makes a lot of sense. I really appreciate the help. I think you have put me on the right track. I have done some additional reading and found the process I plan to use to resolve this issue. http://apple.stackexchange.com/questions/136590/how-can-i-delete-a-partition-cor estorage-logical-volume-from-the-terminal

The good news is that only one of the volumes is reporting being a part of a logical disk group and it happens to be a single partition backup drive that is not hosting live data. I also have at least one other backup so I think I am pretty safe to try this process.

I will either try this on the server backup drive in the next two weeks OR I will will try it on the other machine as that may be much easier to test the process and get results faster. I will report my results.

Jul 18, 2015 10:31 AM in response to Adam Wunn

I've had the same issue with a 6TB Hitachi NAS edition (7200rpm) that I use for Time Machine (on a Mac Pro 4.1 although upgraded now). It was formatted as a GUID single volume with disk utility.

There was never an issue with the Hitachi 3TB and 4TB disks I've got and physically the 6TB installed fine with the stock drive sled (I actually only read about the different screw locations on some models later).

Once recognised it works fine and as I sleep my Mac usually it isn't an issue but whenever I install an update that needs a restart I then have to immediately do a shutdown and cold start after this to get the drive recognised again.

Hitachi support said "Based on the configuration you are using, it seems that the 6TB disk doesn't have enough time to spin up on reboot in comparison with the 3 and 4 TB disks. The firmware update is not related to this issue, it is more a capacity related issue."

At some point I'll try another brand of 6TB but at the time this was the only affordable 7200rpm model.

Jul 18, 2015 10:36 AM in response to Matthew Wilson5

FYI Thinking about it I also added a 5TB Toshiba drive to a Mac Pro 1.1 at work more recently and haven't seen the issue with that.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

6TB drives won't mount after restart in Mac Pro 2012